Drying apparatus



June 21, 1949. B. R. ANDREWS DRYING APPARATUS 2 Sheets-Sheet 1 FiledNov. 16, 1944 June 21, 1949.

B. R. ANDREWS DRYING APPARATUS 2 Sheets-Sheet 2 Filed Nov. 16, 1944Invni'or: Bewaaawd 84422018 8108 Patented June 21, 1 949 I 2,473,629- IiUNITED STATES PATENroFFicE name Arr-Animus Bernard R Andrews, Braintree,Mass Application November is, 1944, Serial No. 563336 3 Claims. 263-3)This invention relates to drying apparatus for dryingv cloth or othermaterial in web or sheet form, and especially to a drying apparatus inwhich the drying is accompanied by the combined action of radiant heatand circulating air currents.

The evaporation of moisture from cloth while it is being dried has theeffect of reducing the temperature of the cloth so that when cloth isbeing dried by circulating air currents, the temperature of the clothmay be several degrees lower than the temperature of the circulatingair. The rapidity with which moisture can be evaporated from cloth, orin other words the rapidity with which cloth can be dried, depends to aconsiderable extent on the temperature of the cloth, and the drying ofthe cloth can be speeded up by increasing its temperature.

In the present invention I have provided a novel drying apparatus whichincludes means for circulating a drying current of air or other gaseousdrying medium over the surface of the cloth' or other web material to bedried, in combination with means to project radiant heat on to the clothwhile it is exposed to the circulating air currents, therebyto raise thetemperature of the cloth and thus to speed up the drying operation.

One object of the invention is to provide a novel drying apparatus ofthis type in which radiant heat of a relatively high temperature may beused without danger of over-heating or burning the material to be dried.

A further object of the invention is to provide a novel drying apparatusof the above type in which an open flame may be safely used to generatethe radiant heat.

Further objects of the invention are to improve drying apparatus usingradiant heat in the Fig. 6 is an enlarged sectional view through omiebofthe burners of the radiant heat generating an Referring to thedrawings'the web of cloth or other material to be dried is indicated atI; and it is shown as being conveyed through a drying space 2 in whichthe drying is done, said drying space 2 being defined by an upper wall 3and a lower wall 4, but being open at the ends for the introduction anddischarge of the web material and'also being open, at the sides. Thewalls 3, 4 are both provided with transversely extending nozzles l9,each nozzle having a delivery slot 2|) that extends transversely acrossthe drying space 2. Means are provided for delivering air (preferablyheated air) under pressure through these nozzles and the nozzles arepreferably so arranged and designed that the sheet-like jetof air 2|which is issued from each nozzle will be directed perpendicularlyagainst the cloth. As each sheet-like jet of air under more or less highpressure impinges against the cloth, it is divided into two branchcurrents 22 (see Fig. 3), which flow over the surface of the cloth inopposite directions lengthwise thereof from the point where the Jet 2|of air impinged on the cloth.

The two branch currents 22 formed from two. adjacent sheet-like jets 2|which are directed toward each other will meet each other midway betweenthe two nozzles and there will be formed two cyclonic currents in eachspace between adjacent nozzles as shown by the arrows in Fig. 3. The-airin these cyclonic currents will gradually spiral outwardly and will bedischarged at the open sides of the drying space 2. The construction andoperation of these nozzles is similar to that shown in my Patent No.2,071,015,

blower or fan 28, so that when the fan is in operation air underpressure will be delivered through the duct 25 to the chambers 23, 26,and thus to the nozzles l9. These chambers 23, 24 and the duct 25 andblower 26 are shown as enclosed in a suitable housing 21, which willpreferably have walls of insulating material. The air which has beendischarged from the nozzles l9 and has been moved across the surfaces ofthe web I will be discharged into the space between the chambers 23, 24and the housing 21. The inlet of the blower 2! is open to this space sothat there will be a re-circulation of the air. The blower is shown asbeing operated by a motor 31 through suitable driving connections 32.Any suitable heating means, indicated at 28, may be employed for heatingthe re-circulating air. 30 indicate vents to permit the escape ofmoistureladen air.

Situated at spaced positions along one or both of the walls 3 and l area plurality of radiant heat generating units indicated generally at 5.For drying cloth, I will preferably use such radiant heat generatingunits both above and below the web of cloth and in the constructionherein shown the radiant heat generating units 5 above the cloth I havea staggered arrangement with those below the cloth. Each radiant heatgenerating unit 5 extends transversely of the cloth so that during thetraveling movement of the web i any portion thereof moves past theradiant heat generators successively. Any desired number of these heatgenerating units may be used, and in the construction shown one suchunit is located between each two adjacent nozzles 19.

These radiant heat generating units may be constructed in various wayswithout departing from the invention. As herein shown, each unit whichextends transversely of the web is made up of a plurality of separateburner elements arranged in a row, each burner element having associatedtherewith a body of refractory material, such as fire clay, which isheated by the burner and which generates the radiant heat.

Each burner element is shown as including a cylindrical body member Iiof firebrick or some other refractory material which has its axis atright angles to the web, and which is formed in the face thereof that isdirected toward the web with an annular depression or groove l5 having aconcave wall. Extending axially through each body member 6 is a duct Iwhich communicates with a supply pipe 8 and which leads to the burner 9that is located centrally of the body member 6 at the face thereof thatis directed toward the web I. The duct 1 is constituted by the bore of atubular member I extending axially through the member 6 and having anenlarged end at said face of the body member and also having a bridgepiece I I that carries a cap l2 which is formed with a skirt portionthat is directed rearwardly toward the body 6 and forms with theenlarged end of the tubular member l0 an annular burner slot I3. The capmember I2 is shown as mounted on a stud 14 which is anchored in thebridge piece II.

The combustible mixture which is delivered through the supply pipe 8 isignited at the burner slot l3 of each burner element and the flame fromeach burner slot plays into the inner edge of the annular depression I!of the corresponding body 6 of refractory material, thereby heating thelatter which then generates and projects radiant heat.

Each radiant heat-generating unit is shown as g elements a and theirassociated blocks or members 6.

These burners and their associated members 6 may be mounted directly onthe supply pipe 8, and as herein shown, each tubular member in isprovided near its upper end with a shoulder l8 engaging the top face ofthe member 6 while the lower end of th tubular member screws into anipple section II which is connected to the supply pipe 8. Each nippleI1 is formed with a flange l8, which is received in a recess 29 withwhich the body member 6 is provided on its under side and the block ormember 6 is therefore clamped in position between the shoulder l6 andthe flange ID.

The high velocity currents 2| of heated air cause evaporation ofmoisture from the cloth, and

the speed of such evaporation is greatly increased by the radiant heatwhich is projected on to the cloth and which raises its temperature to apoint at which evaporation of moisture is much accelerated. The rapidlymoving currents 22 of air are also effective in preventing the clothfrom being overheated or burned by the relatively high radiant heat.

I claim:

1. A drying apparatus comprising a drying space through which a web ofthe material to be dried is fed, said drying space having top and bottomwalls and open sides, a plurality of radiant heat generating unitssituated both above and below the web and adapted to project radiantheat against said web, said units being spaced from each other in thedirection of feeding movement of the web material and each extendingtransversely across said space, and means to establish high velocitywhirling cyclonic currents of air between each two adjacent radiant heatgenerating units which prevent the web material from being unduly heatedand which also assists in the drying operation.

2. A drying apparatus comprising a drying space through which a web ofthe material to be dried is fed, said drying space having top and bottomwalls and open sides, a plurality of radiant heat-generating unitsextending transversely across said chamber and spaced from each other inthe direction of the feeding movement of the web, said radiantheat-generating units being situated to project radiant heat against theweb, and means to establish high velocity whirling cyclonic currents ofair between each two adjacent radiant heat-generating units whichprevent the web material from becoming unduly heated and which alsoassist in the drying operation.

3. A drying apparatus comprising a drying chamber through which a web ofmaterial to be dried is fed, a plurality of radiant heat-generatingunits spaced from each other longitudinally of the chamber, each unitcomprising a plurality of cylindrical bodies of refractory materialarranged closely adjacent each other and with their axes at right anglesto the web, the face of each cylindrical body that is directed towardthe web having an annular depression presenting concave walls, each bodyhaving an axial opening, a tubular member in the opening of each bodyhaving an enlarged end at said face of the body and also having a bridgepiece, a cap member secured to said bridge piece and provided with aperipheral annular skirt which is directed away from the web and whichforms with the periphery of the enlarged portion of the tubular memberan annular burner opening directed toward the annular debeing made up ofa row of these individual burner 7 pression in the body and away fromthe web, said 5 tubular member constituting a fuel-supply duct, means tosupply gaseous fuel to said duct, a nozzle clement between each twoadjacent radiant heatgenerating units, and means to deliver air underpressure through each nozzle element.

BERNARD R. ANDREWS.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number 6 UNITED STATES PATENTS Name Date Tensfeldt Apr. 1, 1924Richardson Apr. 12, 1938 Hess et al Jan. 6, 1942 Hess et a1. Jan. 6,1942 Grantham June 17, 1947

